CLI command with pre-flight checks for a validator

[tkporter]

Problem

Partners should be able to run a CLI command that confirms their validator has been stood up correctly. This is part of the Hybrid HaaS process (https://www.notion.so/hyperlanexyz/Hybrid-HaaS-67195982e71b42de92bc83038498583a?pvs=4#ca11e1fe300940fc910ff5d8aff515ad) where we want to make sure that partners have set their validator up correctly before things are handed off to AW

Solution

A CLI command that:

• Checks if a validator is announced, and outputs a link to the announced S3 bucket
• Checks that there are signed checkpoints in this S3 bucket
  • the latest checkpoint index should roughly match what's on chain (considering that due to reorg periods, validators don't necessarily sign the tip)

Nice to have

It may be nice to think through how we may want to use this internally -- e.g. should it allow for multiple validator addresses to be supplied as well?